I know people dont like canister filters on their sw
tanks but i had great luck with my fluval 305 on my 55g reef.
Like mentioned though you need to clean it out every week or two tops, it can trap all the nasties and cause water parameter issues if it's not maintained.
As far as running media through it, well, thats the plus of a canister.
I was running filter pads, carbon every other month, gfo
when needed and biomedia rocks which I only rinsed with tank water and reused. pretty simple setup and I maintained 0 nitrates while I was using it. Not the best option for filtration of a saltwater tank but still a viable one.